The present invention relates to improvements in friction-driven live roller conveyors for pressureless accumulation loads, whether regularly spaced or not.
In materials handling the practical interest of accumulating industrial or commercial loads for insuring the regular operation of machines, processing equipment, packaging machinery and the like has long been recognized. Abutment systems are thus known which hold back accumulated loads by contact with a relatively small force.
More recently, conveyors have been proposed comprising successive sections of disengageable friction driven rollers, or chain and sprocket driven rollers. Each section is equipped with a load detector or sensing means which when sensing a load disengages the friction drive or the chain and sprocket drive from the rollers of the section immediately upstream so that these rollers freewheel or rotate freely and the load carried by this section is slowed and then stopped, and so forth. This arrangement which progressively stops loads along the conveyor has the drawback of requiring an adjustment of the device as a function of the weight of the loads and therefore does not permit the conveyor from handling loads which vary in weight and size from one to another. In addition, the stopping of a load in a section remains uncertain as does satisfactory accumulation operation.